AEPINUS ATOMIZED. 



835 



niean an atom of pondérable matter, whether it has any electrions within 

 il or not. 



§ 3. In virtue of the discovery and expérimental proof by Cavendish 

 and Coulomb of the law of inverse square of distance for both electric 

 attractions and repulsions, we may now suppose that the atoms, which 

 I assume to be ail of them spherical, repel other atoms outside them 

 with forces inversely as the squares of distances between centres; and 

 that the saine is true of electrions, which no doubt occupy imite spaces, 

 although at présent we are dealing with them as if they were mere 

 mathematical points, endowed with the property of electric attraction 

 and repulsion. We must now also assume that every atom attracts 

 every electrion outside it with a force inversely as the square of the 

 distance between centres. 



§ 4. My assumption that the electrions freely permeate the space 

 occupied by the atoms requires a knowledge of the law of the force 

 experienced by an electrion within an atom. As a tentative hypothesis, 

 I assume for simplicity that the attraction experienced by an electrion 

 approaching an atom varies exactly according to the inverse square of 

 the distance from the centre, as long as the electrion is outside; has no 

 abrupt change when the electrion enters the atom; and decreases to zéro 

 simply as the distance from the centre when the electrion, approaching 

 the centre, is within the spherical boundary of the atom. This is just 



„years ago by Faraday, suggests a convenient modification of it; electrion, to 

 „denote an atom of resinous electricity. And now, adopting the essentials of 

 „Aepinus' theory, and dealing with it according to the doctrine of Father 

 „Boscovich, each atom of pondérable matter is an électron of vitreous electri- 

 „city; which, with a neutralizing electrion of résinons electricity close to it, 

 „produces a resnlting force on every distant électron and electrion which varies 

 „inversely as the cnbe of the distance, and is in the direction determined by 

 „the well-known requisite application of the parallelogram of forces." It will 

 be seen that I had not then thonght of the hypothesis suggested in the présent 

 communication, that while electrions permeate freely through ail space, whether 

 occupied only by ether or occupied also by the volumes of finite sphères con- 

 stituting the atoms of pondérable matter, each electrion in the interior of an atom 

 of pondérable matter expériences electric force towards the centre of the atom, 

 just as if the atom contained within it, fixed relatively to itself, a uniform 

 distribution of idéal electric matter. 



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